Field of the Invention
The present invention relates to alpha-amylases, polynucleotides encoding the alpha-amylases, methods of producing the alpha-amylases, and methods of using the alpha-amylases. In embodiments of the present disclosure, raw starch degrading activity is improved.
Description of the Related Art
Enzymatic degradation of starch is part of many industrial processes including brewing, production of glucose or high fructose syrups and production of drinking or fuel ethanol. In its natural state, starch is quite resistant against degradation by many enzymes, and therefore industrial enzymatic degradation of starch is traditionally initiated by a heating step where starch is gelatinized, which renders the starch more sensitive to many enzymes. Some enzymes are able to act on ungelatinized starch, and are commonly referred to as having raw starch degrading activity. The use of these enzymes permits for improved processes, including, for example, reducing the heating step in processing starch.
Alpha-amylases (alpha-1,4-glucan 4 glucanohydrolases, EC. 3.2.1.1) constitute a group of enzymes which catalyze hydrolysis of starch and other linear and branched 1,4 glucosidic oligo and polysaccharides. Alpha-amylase enzymes have been used for a variety of different industrial purposes, including starch liquefaction, ethanol production, textile desizing, textile washing, starch modification in the paper and pulp industry, brewing, and baking.
WO 2010/091221 discloses a polypeptide having alpha-amylase activity from Aspergillus terreus. Database UniProt XP002576027 discloses the nucleic acid sequence from the Q00881 (Aspergillus terreus) genome for an alpha-amylase.
WO 2008/080093 discloses alpha-amylases and glucoamylases and their use in making biofuel.
There remains a need in the art for improved alpha-amylases, including alpha-amylases that have raw starch degrading activity.